Well tool anchoring device



June 5, 1956 M. o. JOHNSTON 2,748,872

WELL TOOL ANCHORING DEVICE Filed OC'L. 4, 1954 3 Sheets-Sheet l A TTORNEVS June 5, 1956 M. o. JOHNSTON WELL Tool. ANCHORING DEVICE 5 Sheets-Sheet 2 Filed Oct. 4, 1954 INVENTOR.

ATTORNEYS June 5, 1956 Mfo. JOHNSTON 2,748,872

WELL TOOL ANCHORING DEVICE Filed OCt. 4, 1'954 3 Shee/S-Sheet 3 AT TOR/VEYS WELL TOOL ANCHORING DEVICE Mordica 0. Johnston, Glendale, Calif., assigner of onefonrth to Madge Johnston, one-twelfth to Edgar C. lohnston, Jr., one-twelfth to Gordon C. Johnston, and one-twelfth to Joseph Glenn Johnston, ali of Longview, Tex., and one-eighth to Mordica O. Johnston, Jr., La Jullie? and one-eighth to Warren C. iohnston, Glendale, Cal' Application October A4, 1954, Serial No. 460,118

6 Claims. (Cl. 16d-206) This invention relates to a device for anchoring various tools used in oil wells.

The invention is an improvement of the device shown in my copending application entitled Anchor for Well Tools, Serial No. 434,855, filed lJune 7, 1954.

it is the principal object of this invention to provide an achoring device such as disclosed in said copending application, wherein auxiliary dogs adapted to engage the well bore are used to assist in the setting of the main supporting dogs.

A further object of this invention is to `provide an anchoring device as set forth in the preceding object, wherein the auxiliary dogs are relatively flexible and capable of bending upwardly to release, if for any reason'the main dogs should fail to engage the bore wall. l

The invention -is exemplified in the following description and illustrated by way of example in the accompanying drawings, in which:

Figs. 1 and 2 each show a sectional view taken through the upper and lower parts, respectively, of a structure embodying the principles of my invention, and show the various elements in their latched position, 'the plane of the section in Fig. l being rotated between each set of dogs so that -one dog of each set will show in full lines.

Figs. 3 and 4 are similarview to Figs. 1 and `2 and show the parts in their extended relation.

Fig. `5 isa sectional View taken on line 5 5 of Fig. 3.

Fig. 6 isa sectional View taken on line 6-6 of Fig. 2, and illustrates the construction of the auxiliary dogs.

Fig. 7 Vis 1a sectional view taken -on line '7-7 of Fig. 4.

Fig. 8 is a sectional view taken on line 8-3 of Fig. 4.

Figs. 9 and 10 are similar viewsy to those shown in Figs. 1 and 2 and illustrate a modification of the latch structure.

Referring lnow to the drawings, wherein similar reference numerals are used to designate the same elements 'throughout the various views shown, and 'more particularly referring to Fig. l thereof, fit) designates "a 'mandrel adapted to be connected at its upper end to the lower end of a well tool (not shown).

A plurality of main wall engaging dogs 12 are mounted on said mandrel in sets of three. The dogs of each set are spaced 120 from each other around the periphery of the mandrel, and the dogs of each set are offset with respect to the dogs of the other sets in the manner shown in Fig. 5. Each .set of the dogs is spaced vertically from the other sets. Each of the dogs l12 is pivotally attached to the mandrel 10 by a pivot pin 13, 'which `extends through the upper end of the dog and is 'fixed tothe mandrel 10. The dogs 12 are received in recesses 14 for-med in the mandrel 10 whereby, when retracted, the dogs do not extend beyond the periphery of the mandrel with the exception of the outwardly 'extending projection 15 Vformed at the lower end of each of the dogs l12. The lower surface 16 of each of the dogs 12 extends downwardly and outwardly, when vvthe dogs 'are in their retracted position.

1nitccl States Patent iatented .lune 5,1956

A sleeve 17 is slidably mounted on the mandrel 10 and normally encompasses the dogs 12 in the manner shown in Fig. l to hold the dogs in their retracted position. A lplurality vof vertically extending slots 18 are formed in the sleeve 17 and the projecting portions 15 of the dogs 12 are received in said slots. The lower end of each 'of the slots 1S is formed with a downwardly and outwardly tapered surface 19, which `cooperates with the surface 16 on each of the dogs 12 to pivot said dog outwardly, when the sleeve 17 is moved upwardly relative to the mandrel 10 Vto the position shown in Fig. 3. A stud 20 is threaded into the mandrel 10 and the head 21 thereof is received within a longitudinally extending slot 22 in the sleeve 17 to prevent relative rotation between said sleeve and mandrel.

A mandrel extension member 23 of smaller diameter than the external diameter of the mandrel 10 is threaded into the lower end of the mandrel 10 and extends downwardly therefrom. A second sleeve 24 is slightly mounted on the mandrel extension 23 and is provided with an external .iiange 25 welded thereto adjacent its upper end. The flange 25 is adapted to abut against the lower surface of an internal ange 26 welded to the sleeve 17. A collar 27 is threaded into the lower end of the sleeve 17 and abuts the lower surface of the ange 25, thus interconnecting the sleeves 24 and 17 for longitudinal movement as a unit but permitting rotative movement of the sleeve 24 relative to the sleeve 17.

Three pairs of radially extending flanges 25a and 25 arel fastened to the outer surface of the sleeve 24 and extend radially outwardly therefrom. The flanges 25a and '26 in each pair are parallel to each other. As best seen in Fig. 7, three auxiliary dogs 27 are pivotally mounted one vbetween the lianges of each pair of anges 25a and v26 by pivot [pins 28, which extend through the upper 'end of each of the dogs 27 and through the two flanges 25a and 26 associated therewith. Each of the dogs 27 has an upwardly extending lug 29 adapted to abut the surface of the mandrel extension 23 to prevent outward 'pivotal movement of the dogs 27, when the parts are in 'the latched relation illustrated in Fig. 2, and adapted to be received in slots 30 in said mandrel extension 23 to lpermit vsaid outward pivotal movement, when the parts are in the position illustrated in Fig. 4.

As best seen in Figs. 2 and 4, each of the auxiliary dogs 27 has the upper outside corner thereof notched in the manner indicated at 31. A cantilever type spring 32 is 'fastened at one 'of its ends to the sleeve 24 between each pair of anges 25a and 26 above the dog 27 associated therewith by a pair of cap screws 33. The opposite vend of each spring 32 is received in the notch 31 on lone of lthe dogs 27 and urges said dog to pivot outwardly.

Referring now to Fig. 6, each of the dogs 27 comprises an upper end `portion 34 having a transverse bore 35 extending therethrough adapted to receive the pivot pin 28 previously described. A plurality of close wound spiral springs 36 are each connected to the upper member 34. The springs are arranged in a plane parallel to the axis of the bore 35. A lower wedge-shaped member 37 is connected to lthe lower ends ofthe springs SP6, with the axis .of the wedge coincident with the plane of the springs. yRubber material 38 is moulded through and around the springs 36 and iills the space between the upper member 34 and the lower member 37. The pointed lower 'end of 'the lower member 37 is serrated in the manner indicated at 39.

lReferring now to Figs. 2, 4 and 8, apin 40 is threaded into the sleeve l24 and lextends inwardly therefrom. The vpin 40 is received in a J-slot 41 formed in the mandrel extension 23. As best seen in Fig. 8, the J-slot 41 has aflong vertical portion 42, a relatively 'short 'vertical portion 43, and an inclined portion 44 which connects the lower ends of the two vertical portions.

A drag assembly, generally indicated at 45, is attached to the sleeve 24 below the auxiliary dogs 27. The drag assembly comprises bow springs 46 attached at their upper ends to an upper collar 47 by suitable fastening members 48 and at their lower ends to a lower collar 49 by suitable fastening members 50. The upper collar 47 is free to slide relative to the sleeve 24, and the lower collar 49 is fixed to the sleeve 24 as indicated at 51, for example by welding.

A rod 52 is threaded into the lower end of the mandrel extension 23 and extends downwardly therefrom. A spring retainer 53 is fastened to the lower end of the rod 52 by a suitable nut 54 threaded thereon. A compression spring 55 is confined between the spring retainer 53 and an annular abutment 56 held within the sleeve 24 by suitable bolts 57.

The spring 55 normally urges the sleeve 24 upwardly relative to the mandrel extension 23. A sleeve 58 surrounds the rod 52 within the spring 55 and acts both as a spring guide and as a stop member to limit upward movement of the rod 52 and the mandrel extension 23 connected thereto relative to the sleeve 24. A protecting shoe 59 is threadedly connected to the lower end of the sleeve 24 and surrounds the lower end of the rod 52 to protect the same from damage as the tool is lowered into a well. The shoe 59 is provided with a plurality of ports 60 to permit well uid to enter and leave the shoe as the various parts are moved relative to each other.

ln the use of the anchoring device, the parts are assembled and latched in the relationship shown in Figs. 1 and 2. In this condition the device is lowered into the well bore. When the device has reached the desired depth, it is raised slightly. When the device is raised, the drag assembly 45 in contact with the wall bore retards the sleeve 24 and permits the mandrel 10 and man drel extension 23 to move upwardly relative thereto, to move the pin 40 to the lower end of the small portion 43 of the J-slot 41. The mandrel is then rotated to bring the longer portion 42 into alignment with the pin 40. The rotation of the mandrel extension 23 to this position aligns the slots 30 with the lugs 29 on the auxiliary dogs 27. The mandrel is then lowered relative to the sleeve 24.

Upon initial downward movement of the mandrel extension 23 relative to the sleeve 24, the slots 30 are brought into register with the lugs 29 and permit the springs 32 to pivot the auxiliary dogs 12 outwardly to the position shown in Fig. 4. The pointed ends of the dogs enter the side wall of the bore to help the drag assembly 45 hold the sleeves 24 and 17 stationary, as the mandrel l() and the mandrel extension 23 are further lowered to set the main anchoring dogs 12.

lf for any reason the main dogs 12 fail to set; for example, if they should happen to be located opposite an excessively wide portion of the bore, and the full weight is set on the auxiliary dogs 27, the auxiliary dogs 27 are adapted to bend upwardly around the outer face of the upper member 34 thereof in the manner shown in the dot-dash lines of Fig. 4. In this manner, the dogs 27 will release from the well bore and the tool may be raised to again attempt setting thereof. lt can be seen from the construction of the auxiliary dogs 27 that they are capable of sustaining substantial axial loads, while still being capable of bending in the manner described without damage.

Referring now to Figs. 9 and 1G, the modification shown therein is similar in all respects to that shown in Figs. l and 2 with a few changes as detailed herebelow. The slots 30 in the mandrel extension 23 have been replaced by an annular groove 61 to permit the auxiliary dogs 27 to function regardless of the rotational orientation of the mandrel extension 23 relative to the sleeve 2.4.

The Jslot and pin latch assembly of the modification shown in Figs. l to 8, inclusive, has been replaced by a split nut latch assembly such as shown in my above mentioned copending application. ln this latch assembly, a rod 62 is threaded into the lower end of the mandrel extension 23 and extends downwardly therefrom. A downwardly facing buttress thread 63 is formed on the outer surface of the rod 62. A collar 64, having an inwardly facing ange 65, is welded to the inner surface of the sleeve 24 in the manner indicated at 66. An expansible nut 67 is mounted within the collar 65. The expansible nut 67 is urged toward its collapsed position by spring means (not shown) in a manner fully described in my above mentioned copending application. The inner surface of the expansible nut 67 is formed with a buttress thread to match the thread on the rod 62. A collar 68 is threaded into the lower end of the collar 64 and retains the expansible nut 67 therein.

A spring guide 69 surrounds the lower end of the rod 62. An external flange 70 is formed adjacent the upper end of the spring guide 69 and abuts the lov/er end of the collar 68. A spring 71 surrounds the spring guide 69, with its upper end abutting against the undersurface of the flange 70 and its lower end abutting a nut 72 threaded onto the lower end of the rod 62. A lock nut 73 is similarly threaded onto the rod 62 and abuts the nut 72.

The operation of this modification is the same as described above with respect to the modification shown in Figs. l to 8, inclusive, with Ithe exception that the latch is released by rotation of the mandrel 10, mandrel extension 23 and the rod 62 relative to the sleeve 24, to unthread the mating buttress threads on the rod 62 and the cxpansiblc nut 67.

In order to relatch the assembly, it is merely necessary to pull upon the mandrel 10 and its associated parts, and the buttress 'thread 63 or the rod 62 will ratchet into the expansible nut 67.

While I have shown the preferred forms of my invention, it is to be understood that various changes may be made therein by those skilled in the art, without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. In a device for anchoring well tools comprising a mandrel, a plurality of main supporting dogs pivotally mounted on the mandrel, a sleeve slidably mounted on said mandrel and adapted to move said dogs from an inactive to an active position, and a wall engaging drag assembly on said sleeve adapted to frictonally engage the wall of the well bore, the improvement comprising a plurality of auxiliary wall engaging dogs pivotally mounted on said sleeve to pivot from a retracted position to a wall engaging position, spring means biasing said auxiliary dogs toward their active position, means on said auxiliary dogs adapted to abut said mandrel to prevent outward movement of said auxiliary dogs, slots in said mandrel adapted to be brought into register with said last mentioned means to permit outward pivotal movement of said dogs, whereby said auxiliary dogs will bite into the bore wall and aid the drag assembly in holding said sleeve while said mandrel is moved relative thereto to set said main supporting dogs.

2. In a device for anchoring well tools comprising a mandrel, a plurality of main supporting dogs pivotally mounted on the mandrel, a sleeve slidably mounted on said mandrel and adapted when moved longitudinally relative to said mandrel to move said dogs from an inactive to an active position, and a wall engaging drag assembly on said sleeve adapted to frictionally engage the wall of the well bore, the improvement comprising a plurality of auxiliary wall engaging dogs pivotally mounted on said sleeve to pivot from a retracted position to a wall engaging position, spring means biasing said auxiliary dogs toward ytheir active position, means on said auxiliary dogs adapted to abut said mandrel to prevent outward pivotal movement of said auxiliary dogs, slots in said mandrel adapted to be brought into register with said last mentioned means upon rotation of said mandrel relative to said sleeve to permit outward pivotal movement of said dogs, whereby said auxiliary dogs will bite into the bore wall and aid the drag assembly in holding said sleeve While said mandrel is moved downwardly relative thereto to` set said main supporting dogs.

3. In a device for anchoring well 'tools comprising a mandrel, a plurality of main supporting dogs pivotally mounted on the mandrel, a sleeve slidably mounted on said mandrel and adapted to move said dogs from an inactive to an active position, and a wall engaging drag assembly on said sleeve adapted to frictionally engage the wall of the well bore, the improvement comprising a plurality of auxiliary wall engaging dogs pivotally mounted on said sleeve to pivot from a retracted position to a wall engaging position, spring means biasing said auxiliary dogs toward their active position, stop means on said auxiliary dogs adapted to abut said mandrel to prevent outward pivotal movement of said auxiliary dogs, an annular groove in said mandrel, the bot-tom of said groove being adjacent to and above said stop means, whereby initial downward movement of said mandrel will bring said groove into register with said stop means to permit said auxiliary dogs to pivot outwardly and bite into the bore wall and aid the drag assembly in holding said sleeve while said mandrel is moved relative thereto to set said main supporting dogs.

4. In a device of the character described, a wall engaging dog comprising an upper rigid member adapted to be pivotally attached to a well tool, a lower rigid member terminating in a pointed end, an intermediate portion xed to both the upper and lower members, said intermediate portion comprising a plurality of close wound spiral springs the axes of which extend longitudinally of said dog, whereby said dog is relatively rigid when subjected to axial loads but relatively exible when subjected to bending stresses.

5. In a device of the charac-ter described, a wall engaging dog comprising an upper rigid member adaptedto be pivotally attached to a well tool, a lower rigid member terminating in a pointed end, an intermediate portion fixed to both the upper and lower members, said intermediate portion comprising a plurality of adjacent close wound spiral springs, all of said springs being in the same plane, whereby said dog is relatively rigid when subjected to axial loads but relatively flexible when subjected to bending stresses.

6. In a device of the charac-ter described, a wall engaging dog comprising an upper rigid member adapted to be pivotally attached to a well tool, a lower rigid member terminating in a pointed end, an intermediate portion xed to both the upper and lower members, said intermediate portion comprising a plurality of adjacent close wound spiral springs, all of said springs being in the same plane, said springs being embedded in a block of elastomer material bonded to said springs and to said upper and lower members, whereby said dog is relatively rigid when subjected to axial loads but relatively flexible when subjected to bending stresses in a direction other than the plane of said springs.

References Cited in the file of this patent UNITED STATES PATENTS 

